This invention relates to the continuous casting of molten metal. It relates particularly to the construction of a tundish used to control the flow and improve the quality of the molten metal before it is cast.
In the continuous casting of molten metal, such as steel, the molten metal is brought to the casting machine in a bottom pour ladle and is poured into a refractory lined tundish positioned over the mold in the continuous casting machine. The tundish serves as a reservoir of molten metal at constant head and also allows most of the impurities in the molten metal to float out of the metal before it is cast. Some tundishes use special slags and baffles to assist in the removal of the impurities. In the case of steel, aluminum oxide is an undesirable impurity since it will cause serious inclusions in the cast steel but aluminum oxide particles have been difficult to remove.
Metal producers have tried to use ceramic filters in the tundish in an attempt to filter out the impurities. While such filters have been somewhat successful with low temperature melting pint metals, such as aluminum, zinc and lead, they have not proven successful with high temperature molten steel. Such filters have tended to clog with tundish slag and restricted the uniform flow of the molten steel from the tundish to the continuous casting mold.